Preserving container closure, vent, and seal



May 30, 1939.

R. B. BU KOLT 2,160,429

PRESERVING CONTAINER CLOSURE, VENT, AND SEAL Filed May 14, 1935 PatentedMay 30, 1939 UNITED STATES PRESERVING CONTAINER CLOSURE, VENT, AND SEALRoman B. Bukolt, Stevens Point, Wis.

Application May 14, 19-35, Serial No. 21,450

14 Claims. (01. 215-56) The invention relates to containers used forpreserving fruits and vegetables, and it aims to make novel provisionfor venting air from the container during the heating of the jarcontents for preservation purposes, and for sealing the vent to preventreturn of air to the container as the contents cool.

The invention is shown in connection with a container closure of thegeneral type disclosed in my U. S. application Serial No. 719,961, filedApril 10, 1934, or my U. S. application Serial No. 757,575, filedDecember 14, 1935,. but such showing is for illustrative purposes onlyand the present invention may be embodied with any type of closureproperly constructed to permit the venting and sealing hereinafterdescribed;

Figure 1 of the accompanying drawing is a sectional view through aclosure disk provided with a conical depression and a vent hole, thevent 0 seal being shown partly in section and partly in elevation abovesaid depression.

Figure 2 is a sectional view showing the closure applied to the neck ofa conventional jar and illustrating the manner in which the seal is 5affected by the heat of the usual preserving process.

Figures 3 and 4 are views similar to Figs. 1 and 2 but showing a flatbottomed depression and the seal in the form of a disk instead of aball.

The form of closure with which the present improvements have beenillustrated, comprises a substantially concavo-convexlever-and-toggleaction snap-disk5, an attaching ring 6 to engage the jarneck, and a gasket 1, the disk 5 being so shaped that when it is snappeddownwardly from the position shown in the drawing, either by handpressure or by vacuum within the jar, it forcibly compresses the gasketto prevent leakage.

At any suitable location, but preferably at its center, the disk 5 isprovided with a depression 8 and with a pin hole vent 9 in the bottom ofthe depressed portion. Receivable in the depression 8 is a sealcomprising a slug l0 and a thermo- 5' plastic coating H for said slug.The slug may be in the form of a ball as shown in Figs. 1 and 2 and thecoating 1 l correspondingly shaped, or said slug may be a disk as shownin Figs. 3 and 4 with the coating shaped accordingly.

The slug I0 is formed from metal or other appropriate material whichwill be unchanged by the temperatures used in preserving, lead beingpreferably employed at least when the slug is in the form of a ball, sothat ordinary lead shot 55 may be used.

The thermo-plastic coating ll preferably com- -prises pitch, bitumen orthe like and a quantity of dry Portland cement or pulverized earth mixedtherewith.

After heating the container contents to the proper temperature and forthe appropriate time during the preserving process, and thereby drivingout air with the steam escaping through the vent hole 9, the seal In, His dropped into the depression 8. The heat from the container and itscontents immediately causes the thermo-plastic composition to flow aswill be clear from Figs. 2 and 4, and if any pressure be still escapingfrom the container, it will bubble through the seal. While thethermo-plastic composition is fluid, the Portland cementor pulverizedearth therein settles to the bottom as denoted at 12 to form aneffective seat for the slug l0 and to prevent any of the pitch or thelike from entering the container. As long as the pressure within thecontainer is greater than atmospheric, this pressure will pass throughthe seal to the atmosphere but as the contents cool and the pressurewithin the container becomes negative, the slug I0 acts as a check valveand the sealing medium cooperates with it to positively prevent anyentrance of air into the container.

When a snap disk cover is used as herein disclosed, upward snapping ofthe disk relieves the pressure on the gasket 1 and allows easy openingof the jar. the disk to snap upwardly or to facilitate upward snappingthereof, an ordinary pin may be forced through the sealing materialthereby admitting air to the vent hole 9.

As excellent results are obtainable from the details disclosed, they arepreferably followed. However, within the scope of the invention asclaimed, variations may, of course, be made.

I claim:

1. A preserving container closure provided with a depression and with avent hole in the bottom of said depression, a downwardly closing checkvalve for said vent hole positioned within said depression, and a sealwithin said depression and cooperable with said check valve in sealingsaid vent hole, said seal consisting of a lower stratum of thermallyunchanged powder forming a seat for said check valve, and athermo-plastic upper stratum covering said lower stratum andfluidtightly engaging said check valve and said depression.

2. A preserving container "closure provided with a depression and witha' vent hole in the bottom of said depression, a thermally unchangedslug To relieve the vacuum and allow v within said depression, and athermo-plastic seal within said depression cooperable with said slug insealing said vent hole, said seal consisting of a lower stratum ofthermally-unchanged powder forming a seat for said slug, and an upperthermo-plastic stratum covering said lower stratum and fluid-tightlyengaging said slug and said depression.

3. In a seal of the class .described, a thermallyunaffected slug coatedwith a sealing composition, said sealing composition comprising athermallyunchanged sealing powder embedded in a thermoplastic substance.

4. A structure as specified in claim 3; said slug being in the form of aball.

5. A structure as specified in claim 3; said slug being in the format aflat disk.

6. A preserving container closure provided with a depression and with avent hole in the bottom of said depression, and a seal within saiddepression closing said vent hole, said seal comprising a lower stratumof thermally-unaffected powder cooperable with said check valve insealing said vent hole, said seal consisting of a lower stratum ofthermally unchanged powder forming a seat for said check valve, and aplastic upper stratum covering said lower stratum and fluid-tightlyengaging said check valve and said depression.

10. A preserving container closure provided with a depression and with avent hole in the bottom of saiddepression, a thermally unchanged slugwithinsaid depression, and a plastic seal Within said depressioncooperable with said slug .insealing said vent hole, said sealconsisting of alower stratum of thermally-unchanged powder forming aseat for said slug, and an upper plastic stratum covering said lowerstratum and fluidtightly engaging said slug and said depression.

11. In a seal of the class described, a thermallyunaffected slug coatedwith a sealing composition, said sealing composition comprising athermally-unchanged sealing powder embedded in a plastic substance. I

12. "A preserving container closure provided with a depression and witha vent hole in the bottom of said depression, and a seal within saiddepression closing said vent hole, said seal comprising a lower stratumof thermally-unaffected powder and an upper plastic stratum coveringsaid'ilower stratum.

13. A preserving container closure provided with a vent; and a seal forsaid vent comprising a thermally unaiTected powder mixed with a plasticsealing substance.

14. In a seal of the classdescribed, Portland cement mixed with aplastic sealing substance.

--a ROMAN B. BUKOLT.

